Firearm Lower Receiver And Method of Use

ABSTRACT

A firearm lower receiver and method of use may include a screw disposed to engage a pin housing in an upper receiver to minimize rattling or vibration between the upper receiver and the lower receiver.

BACKGROUND State of the Art

The present invention relates to a lower receiver for firearms which reduces rattle when engaged with the upper receiver.

Field of Art

Certain types of automatic and semi-automatic weapons, such as an AR-10 and an AR-15 rifle, include an upper receiver and a lower receiver which are removably attached to one another. To gain access to the interior of the receiver, a takedown pin is removed, thereby allowing the upper and lower receiver to pivot with respect to one another. A pivot pin at the opposing end of the upper and lower receivers can also be pulled to allow the upper and lower receivers to be released from one another.

While the upper receiver and the lower receiver may be in relatively snug engagement with one another when the takedown pin and pivot pin are securely in place, a rifle made with lose tolerances or a rifle which has received extensive use may allow rattling between the upper and lower receiver. This rattling may increase gun vibration, especially if the weapon is being used in automatic mode or being fired semi-automatically at a high rate of fire.

SUMMARY OF THE INVENTION

The following summary of the present invention is not intended to describe each illustrated embodiment or every possible implementation of the invention, but rather to give illustrative examples of application of principles of the invention.

The invention may comprise a screw accessible through the pistol grip which engages the bottom of the takedown pin housing in the upper receiver to push the takedown pin housing into contact with the take down pin.

In one embodiment, the screw may include a set screw which engages the takedown pin housing which is accessible through a pistol grip attached to the lower receiver.

The invention may comprise a set screw in the lower receiver which is accessible above a thumb trigger to allow the set screw to be tightened and thereby force the takedown pin housing into engagement with the take down pin, and can be loosened to allow the break-down pin to be removed from the takedown pin housing to facilitate opening of the upper and lower receivers.

These and other aspects of the present invention are realized in trigger mechanism for firearms which can be actuated by the user's thumb. The trigger mechanism may provide increased safety and potentially increased accuracy while firing the weapon.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure are shown and described in reference to the numbered drawings wherein:

FIG. 1 shows an exploded side view of a conventional upper receiver and a lower receiver having a screw disposed therein;

FIG. 2 shows a fragmented top view of the lower receiver of FIG. 1;

FIG. 3 shows a side view of a lower receiver having a thumb activated trigger and a screw for more securely engaging the upper receiver and the lower receiver;

FIG. 4 shows a close-up view of the takedown pin disposed inside the takedown pin housing; and

FIG. 5 shows an alternate embodiment of the screw mechanism and takedown pin body.

It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It will be appreciated that it is not possible to clearly show each element and aspect of the present disclosure in a single figure, and as such, multiple figures are presented to separately illustrate the various details of different aspects of the invention in greater clarity. Similarly, not all configurations or embodiments described herein or covered by the appended claims will include all the aspects of the present disclosure as discussed above.

DETAILED DESCRIPTION

Various aspects of the invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The skilled artisan will understand, however, that the apparatus and methods described below can be practiced without employing these specific details, or that they can be used for purposes other than those described herein. Indeed, they can be modified and can be used in conjunction with products and techniques known to those of skill in the art in light of the present disclosure. The drawings and the descriptions thereof are intended to be exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. Furthermore, it will be appreciated that the drawings may show aspects of the invention in isolation and the elements in one figure may be used in conjunction with elements shown in other figures.

Reference in the specification to “one embodiment,” “one configuration,” “an embodiment,” or “a configuration” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment, etc. The appearances of the phrase “in one embodiment” in various places may not necessarily limit the inclusion of a particular element of the invention to a single embodiment, rather the element may be included in other or all embodiments discussed herein.

Furthermore, the described features, structures, or characteristics of embodiments of the present disclosure may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details may be provided, such as examples of products or manufacturing techniques that may be used, to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that embodiments discussed in the disclosure may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations may not be shown or described in detail to avoid obscuring aspects of the invention.

Before the present invention is disclosed and described in detail, it should be understood that the present invention is not limited to any particular structures, process steps, or materials discussed or disclosed herein, but is extended to include equivalents thereof as would be recognized by those of ordinarily skill in the relevant art. More specifically, the invention is defined by the terms set forth in the claims. It should also be understood that terminology contained herein is used for the purpose of describing particular aspects of the invention only and is not intended to limit the invention to the aspects or embodiments shown unless expressly indicated as such. Likewise, the discussion of any particular aspect of the invention is not to be understood as a requirement that such aspect is required to be present apart from an express inclusion of that aspect in the claims.

It should also be noted that, as used in this specification and the appended claims, singular forms such as “a,” “an,” and “the” may include the plural unless the context clearly dictates otherwise. Thus, for example, reference to “a bracket” may include an embodiment having one or more of such brackets, and reference to “the target plate” may include reference to one or more of such target plates.

As used herein, the term “substantially” refers to the complete or nearly complete extent or degree of an action, characteristic, property, state, structure, item, or result to function as indicated. For example, an object that is “substantially” enclosed would mean that the object is either completely enclosed or nearly completely enclosed. The exact allowable degree of deviation from absolute completeness may in some cases depend on the specific context, such that enclosing the nearly all of the length of a lumen would be substantially enclosed, even if the distal end of the structure enclosing the lumen had a slit or channel formed along a portion thereof. The use of “substantially” is equally applicable when used in a negative connotation to refer to the complete or near complete lack of an action, characteristic, property, state, structure, item, or result. For example, structure which is “substantially free of” a bottom would either completely lack a bottom or so nearly completely lack a bottom that the effect would be effectively the same as if it completely lacked a bottom.

As used herein, the term “generally” refers to something that has characteristics of a quality without being exactly that quality. For example, a structure said to be generally vertical would be more vertical than horizontal, i.e., would extend greater than 45 degrees from horizontal. Likewise, something said to be generally circular may be rounded like an oval but need not have a consistent diameter in every direction.

As used herein, the term “about” is used to provide flexibility to a numerical range endpoint by providing that a given value may be “a little above” or “a little below” the endpoint while still accomplishing the function associated with the range.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member.

Concentrations, amounts, proportions, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also include individual values and sub-ranges within the indicated range. Thus, included in this numerical range are individual values such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually. This same principle applies to ranges reciting only one numerical value as a minimum or a maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described.

Turning now to FIG. 1, there is shown an exploded side view of an upper receiver 10 and a lower receiver 14. The upper receiver 10 may include an ejection port 18 and an ejection port door 22 to selectively cover the ejection port. Also shown on the upper receiver 10 is a threaded collar 24 and a forward assist 26. At the bottom of the upper receiver 10 is a pivot pin housing 30. Near an opposing end of the upper receiver 10 is a takedown pin housing 34. In use, a barrel (not shown) would be attached at the collar 24.

The lower receiver 14 includes a pair of takedown pin holes 36 (one being on each side of the lower receiver) into which a takedown pin 44 is inserted. A pair of pivot pin holes 40 (one being on each side of the lower receiver) are disposed at the front of the lower receiver 14. Pivot pin holes 40 receive the pivot pin 48. To connect the upper receiver 10 to the lower receiver 14, the hole 30 a in the pivot pin housing 30 is disposed in alignment with the pivot pin hole 40 in the lower receiver 14 and the pivot pin 48 is inserted through the holes 40, 30 a. This allows the upper receiver 10 and the lower receiver 14 to pivot with respect to one another.

The upper receiver 10 is then pivoted with respect to the lower receiver 14 until the hole 34 a in the takedown pin housing 34 is in alignment with the holes 36 in the lower receiver 14. The takedown pin 44 is then inserted through the holes 36, 34 a to thereby hold the upper receiver 10 to the lower receiver 14. It will be appreciated that the cross-sectional area of the hole 34 a in the takedown pin housing 34 will be slightly larger than the cross-sectional area of the pin 44 so that the pin may be inserted into the hole.

The lower receiver 14 also includes a trigger 52 and a magazine port 56. Disposed behind the trigger 52 is a pistol grip 60. In a fully assembled rifle, a buttstock (not shown) having a buffer tube disposed inside would be attached to the mount 72 of the lower receiver 14. As part of the assembly, a detent (not shown) is disposed in contact with the takedown pin 44 to prevent it from accidentally coming out.

As shown in FIG. 1, the pistol grip 60 may include a lumen or channel to access a screw 68. The screw 68 may positioned below the takedown holes 36 so that it can be advanced to engage the bottom of the takedown pin housing 34 when the takedown pin 44 is in place so force the takedown pin housing into contact with the takedown pin, thereby acting as a set screw. The engagement of the screw against the takedown pin housing 34 reduces rattling of the receiver during firing.

Turning now to FIG. 2, there is shown a fragmented top view of the lower receiver 14. The take down pin 44 has been inserted into the holes 36 in the lower receiver 14. The screw 68 is visible below the takedown pin 44. When the takedown pin housing 34 is disposed about the takedown pin 44, advancing the screw 68 will hold the takedown pin housing in firm engagement with the takedown pin and thereby reduce rattle in the receiver. When butting against the takedown pin housing, the screw acts as a set screw. As discussed with respect to FIG. 5, the screw can also be screwed into the takedown pin housing.

Turning now to FIG. 3, there is shown a fragmented side view of a lower receiver 14 with a thumb trigger 52 in a ready-to-fire position. The trigger 52 is disposed above the pistol grip 60 and pivots about a pin set in the trigger pin hole 52a. The trigger 52 may be locked by use of the safety 88.

The lower receiver 14 includes a takedown pin hole 36 and a pivot pin hole 40 disposed near opposing ends. A hammer 76 is seen sticking up from the lower receiver 14 in the middle. A magazine 80 is disposed in the magazine port and may be released by pressing the magazine release 84.

Disposed in the lower receiver 14, generally above the trigger 52 is a screw 68 or other fastener which is designed to forcefully engage the takedown pin housing of the upper receiver (not shown) so that the take down pin housing is forced into contact with the takedown pin when the set screw is tightened. In light of the present disclosure, it will be appreciated that the screw 86 may act as a set screw and may include a flange or collar 92 to facilitate turning the set screw by hand, or it may have a head which requires a screwdriver or hex wrench to turn the set screw.

Turning now to FIG. 4, there is shown a close-up, fragmented view of the takedown pin housing 34 disposed about the take down pin 44. The hole 34 a in the takedown pin housing 34 is typically larger than the takedown pin 44 to facilitate placement and removal of the takedown pin. By advancing the set screw 68, the bottom of the structure defining the hole 34 a in the takedown pin housing 34 is forced up against the takedown pin 44, thereby removing the ability of the takedown pin housing to move relative to the takedown pin.

Turning now to FIG. 5, there is shown an alternate embodiment of the invention. Instead of the screw acting as a set screw which engages the takedown pin housing 34 and forcing it into engagement with the bottom of the takedown pin as shown in FIG. 4, the screw 68 a screws into the takedown pin housing and engages the bottom of the takedown pin to force it into engagement with the takedown pin housing. Thus, the takedown pin housing 34 may include a threaded section 34 b which is engaged by the screw 68 a.

In light of the present disclosure it will also be understood that a set screw or other fastener could be disposed so as to engage the pivot pin housing 30 (FIG. 1) when the pivot pin 48 is disposed in the pivot pin housing to further reduce the potential for rattling or vibration between the upper receiver 10 and the lower receiver 14.

Thus, there is disclosed a trigger mechanism for firearms. It will be appreciated that numerous modifications may be made without departing from the scope and spirit of this disclosure. The appended claims are intended to cover such modifications. 

What is claimed is:
 1. A firearm comprising: An upper receiver and a lower receiver, a takedown pin for selectively attaching the upper receiver to the lower receiver and a screw disposed adjacent the takedown pin.
 2. The firearm of claim 1, wherein the upper receiver has a takedown pin housing which engages the takedown pin.
 3. The firearm of claim 2, wherein the screw is a set screw positioned to engage the takedown pin housing when the takedown pin is disposed in the takedown pin housing.
 4. The firearm of claim 2, wherein the takedown pin housing has a hole having a cross-sectional area and wherein the takedown pin has a cross-sectional area and wherein the cross-sectional area of the hole is larger than the cross-sectional area of the pin.
 5. The firearm of claim 1, further comprising a pistol grip and wherein the pistol grip has a lumen in communication with the screw.
 6. The firearm of claim 1, further comprising a trigger and wherein the screw is disposed above the trigger.
 7. The firearm of claim 1, wherein the lower receiver has holes for receiving the set screw and wherein the screw is a set screw disposed below the holes.
 8. A firearm comprising a lower receiver, the lower receiver having at least one hole for receiving a pin and a set screw disposed adjacent the pin for forcing a pin housing into contact with the pin.
 9. The firearm of claim 8, wherein the at least one hole is disposed toward the back of the lower receiver and wherein the set screw is disposed below the at least one hole for the pin.
 10. The firearm of claim 8, wherein the lower receiver includes a thumb trigger.
 11. The firearm of claim 10, wherein set screw is disposed above the thumb trigger.
 12. The firearm of claim 10, wherein the set screw comprises a flange or collar disposed for manually gripping to allow toolless tightening or loosening of the set screw.
 13. The firearm of claim 8, further comprising an upper receiver, the upper receiver having at least one pin housing.
 14. The firearm of claim 8 further comprising an upper receiver having a pivot pin housing having a hole therein and a takedown pin housing having a hole therein.
 15. The firearm of claim 14, wherein the takedown pin housing is disposed above the set screw when the upper receiver is disposed on top of the lower receiver.
 16. The firearm of claim 15, further comprising a takedown pin extending through the at least one hole in the lower receiver and through the takedown pin housing.
 17. A method for securing an upper receiver to a lower receiver, the method comprising: selecting an upper receiver having a takedown pin housing for engaging a takedown pin; selecting a lower receiver having at least one hole for receiving a takedown pin and a screw for engaging the take down pin housing; disposing the upper receiver and the lower receiver so that the takedown pin housing is in alignment with the at least one hole in the lower receiver; advancing a take down pin into the at least one hole and into the takedown pin housing; and tightening the screw to engage the takedown pin housing and urge the takedown pin housing into contact with the takedown pin.
 18. The method according to claim 17, wherein the takedown pin housing includes a hole and wherein the method comprises placing the takedown pin in the hole in the takedown pin housing prior to advancing the screw.
 19. The method according to claim 18, comprising advancing the screw until a lower surface of a wall defining the hole in the takedown pin housing is forced into contact with the takedown pin.
 20. The method according to claim 18, comprising advancing the screw so that the screw causes the takedown pin to forcefully engage a top of a hole in the takedown pin housing. 